It was the last refresh for the Pontiac Bonneville, a car which was on the market since 1958 and reached its tenth generation in 2000.
GM tried to find new ways to keep the Bonneville nameplate on the market and refreshed it in 2004 for the 2005 model year lineup. Along with the upgraded exterior and new materials for the interior, the car received a V-8 engine carried over from Cadillac. It was the first V-8 Bonneville after 17 years.
Pontiac insisted on keeping its wide stance on the road, and General Motors approved it. Thus, the Bonneville was the widest car built on the GM's G-Platform, which made the carmaker named it as an H-platform. At the front, a clear glass covered the three-lamp headlights, flanking the Pontiac-specific grille with a vertical slat in the middle. A re-designed wrapped-around plastic bumper featured two air-intakes, separated by a wide center element that sported the brand name.
Inside, the Bonneville kept the same design but with a different suede. It featured the same eight vents on the dashboard and the rounded design language. Its front bucket seats were more on the comfort side than on the sporty one. Since it was a full-size sedan, it provided enough room for three adult passengers on the rear bench, thanks to a small center tunnel. The GXP version instrument panel sported white dials with red needles to emphasize the car's sporty character.
Under the hood, apart from the previously used 3.8-liter V-6 naturally aspirated, Pontiac introduced a 4.6-liter Northstar V-8 powerplant that provided 275 hp. Its independent suspension in all corners and the wide track worked well during high-speed cornering, but its standard four-speed automatic transmission was not exactly what the car needed.